Updating VSAN stretched cluster vCenter Foundation

[badkapp]

Hi there,

we have a customer that uses two 2-node VSAN clusters in one vCenter.

vCenter Foundation
Cluster 1: 2 Servers with VSAN Witness Appliance on datacenter level
Cluster 2: 2 Servers with VSAN Witness Appliance on datacenter level

When they updated their environment, updating the ESX-Servers went smooth.

However, after they patched one of their Witness Appliances, vCenter regognized the rebooting Witness as full ESX-Host, and since vCenter Foundation can only manage 4 ESX Hosts, the Witness Appliance got disconnected which left VSAN in Error state.

The only way to solve this was to temporarily change the vCenter license to Standard and add the virtual Witness. After adding, changing back to Foundation worked without issues.

Was this a stupid coincidence or did anybody have similar issues?

I found similar things when building 2+2+1 Stretched Clusters from scratch, and the workaround was to add the Witness Appliance to vCenter before the physical hosts. However this one doesn't work in production environment.

Thanks everybody

[Brisk]

a vSAN witness appliance still runs ESXi at it's core. I suspect that this is why you're getting the license breach. I'm not entirely sure if this will ever work properly.

Your best bet here would be to contact support.

[Jasemccarty]

I recall when I worked at VMware that this came up, and there was fix for it accomplished with a vCenter Server update. 

What version of vSphere/vSAN?

[MJMSRI]

This was indeed an issue that has been fixed in vSphere 6.5 U2, and 6.7 U1 (see VMware vCenter Server 6.7 Update 1 Release Notes )

[TheBobkin]

Just an FYI, while I am aware this documentation refers to vCenter Essentials (limited to managing 3 physical hosts), it is likely this would also apply to vCenter Foundation (but with 4 physical hosts):

https://www.vmware.com/content/dam/digitalmarketing/vmware/en/pdf/products/vsan/vmware-vsan-licensin...

"• The vSAN witness appliance must be added to vCenter prior
to the third physical host being added to vCenter.
• A warning message will be generated when attempting to add
the vSAN witness appliance as a vSAN witness host after the three
physical hosts have been added.
Note: The order of operation is important; vCenter does not recognize the
vSAN witness appliance as a virtual host until after it is added to vCenter"